This follows Mozilla’s announcement that Firefox 4 is ‘unlikely’ to support PPC.
The Opera team cite the reason that only 0.1% of all Opera use PPC – a figure I have no trouble believing since the Mozilla-based Camino browser is more popular with users of OS X PPC, and for Linux users Firefox remains available for now.
By relieving themselves of its burden they can “focus… on our high quality browser to make sure that it meets the need of the modern web browser user on the popular architectures.”